I'll add a couple comments as I was at the hotel a few weeks ago on a FFN award.
Booked whatever was available for FFN and was upgraded to the room type that AZ got.
AZ really covered the room well - the only things I would mention is that breakfast was complimentary for Diamonds and normally 45 YTL (about $30 USD) per person.
I also received a tray of fruit each day of my stay which I presume was the Diamond Amenity, but not quite sure.
Overall, I found the staff at the hotel to be exceptionally friendly.
By the way, I know that Taksim Square is a popular spot for airport transit and other things - it's about a 5 YTL cab ride there or a 20 minute walk